It's so sad to read about problems that can't be solved in Audi A4 B6... I own one! Believe me the only reason I ended up here is how I could replace a burnt headlight... I went through hell to get it replaced.

I've had a lot of problems before with this model. Some that couldn't be traced by professional mechanics. 'Cause I couldn't afford THE STEALER! Going through reading and turning internet pages using three different languages (Norwagian, Dutch and English) helped me solve the problem by myself.
I got a friend who owns A4 B7 since 2007 driving the car with the Check Engine light ON 'cause THE STEALER couldn't and still can't trace the problem... The disadvantage he has is he can't know when there is a problem with the other parts of the car until he hooks up with diagnosis.
I'm telling you Audi cars are wonderful and comfortable cars to drive around but when it comes to maintaining them even a simple burnt bulb change will make you go through hell not to mention oil consumption. You must have extra oil on reserve...
Audi A4 B6 is my first Audi and I'm really saddened to confess its gonna be my LAST...
Good Luck with the PROBLEM. Hope you'll find a solution to your problem. Cheers!

 

I have a 2004 A4 1.8T Q and lately my ESP light will come one first and a couple seconds later my check engine light comes on. I will drive anywhere from 1/4 mile to 10 miles and then the ESP light will go off and the check light light will stay on until I turn the car of and on about 8 times. At times I have plugged in my Actron Pocket Scan Plus OBD II Code Reader and it reads a P0102 Mass Air Flow Circuit error. I can clear the code and there is no difference in performance, which has always been very good. I have noticed that the engine will "stumble" for just a second and and within a second the ESP light comes on and then the check engine light. So I'm just clueless as to what to do. I don't want to go to the dealer, I feel like I am taken advantaged of each time I have gone in the past. I can do all of my own work.
Hope someone has some advise for me.

 

I had this going on as well on my 2005 A4 Quattro. I would be driving and I would briefly lose RPM's. If this happened when I was stopped, the car usually died.

I was kinda freaking out when I was looking through various forums about the EPC light and the vehicle dying. Especially when people were saying even the Audi dealership didn't know what the problem was.

I went to a local shop in town and told them what was going on. About an hour later, they called me and said that, to resolve this problem, I needed:

* A new crank position sensor ($100)
* New spark plugs ($48)
* New coil packs (4 @ $40)

Picked up the car from them and it has been running perfectly for about 2 weeks now.

Just my experience and what seemed to be the resolution for my EPC problem.

-c

 

Since about 2 weeks, my car is hard to start, it takes about 30 second (starter running). Then the engine start and the EPC light come on, enven if that one as been deleted right befor... No check engine or other light come on at this time... WTF??